Figure 7. Oxidative stress evaluation/reactive oxygen species (COO^-, ONOO^-) and mainly hydrogen peroxide production (H₂DCF-DA assay) at 24 h (gray bars) and 48 h (black bars). The results expressed as percentages (means±SD) of the 100% of control DMEM and signals emitted by cell population are reported over the neutral red test as an indication of viable cells. At 24 h and 48 h, compared to control, incubation in BAK5.10−4% and  combinations of any HO with BAK3.10−4% and BAK5.10−4% induced a superoxide anion increase (p<0.001), except for HO50 mM and HO60 mM associated with BAK3.10−4% at 24 h. The following letter codes were used for statistical comparisons with (b) all BAK concentrations, (b1) BAK10−4%, (b3) BAK5.10−4%, (b5) BAK3.10−4%, (h) all HO solutions, (h50) HO50 mM, (h60) HO60 mM, (h90) HO90 mM, corresponding to a statistically significant difference at p<0.001.